Acne
The pilosebaceous gland is a principal source of oil on mammalian skin and scalp. Therefore, a benefit of controlling sebaceous gland activity (sebum secretion) includes a reduction in the level of oil found in skin and hair.
Sebum secretion is also related to acne. Acne is a pilosebaceous disease characterized by comedo, papules, inflamed nodules and superficial pus-filled cysts. The course and severity of acne is determined by the interaction between hormones, keratinization, sebum formation and bacteria. Acne usually begins at puberty, when circulating levels of androgens increase. The pilosebaceous glands increase in size and sebum synthetic activity is elevated due to this increase in circulating levels of androgens. Follicular hyperkeratosis can also occur, causing restriction of pilosebaceous follicles and, consequently, comedo or plug formation. The comedo contains sebum, protein debris, and anaerobic microorganisms including propionibacterium (cotynebacterium) acnes (P. acnes). P. acnes thrives on the sebum and generates inflammatory free fatty acids (FFA). The FFA cause irritation in the follicular wall and can lead to rupture of the follicular wall, inducing an inflamed lesion. In severe cases, this lesion will heal with scarring.
Existing treatments for acne include from general topical application of lotions and salves to affected skin areas, to localized (spot) topical treatment. Products used for such treatments include benzoyl peroxide, sulfur resorcinol, salicylic acid and trans-retinoic acid. The therapeutic value is limited because of poor efficacy, poor aesthetics, and lack of effect on sebum production.
Other effective therapies for acne which reduce sebum production, include the use of antiandrogens, and cis-retinoic acid. However, because of undesirable systemic side effects, such as teratogenecity, pituitary dysfunction, and male sterility, current use is restricted to the more severe cases of acne. Antimicrobials are also somewhat effective in treating acne because they control the growth of P. acnes. The effectiveness of antimicrobials is limited because they do not affect sebum production.
For the foregoing reasons, there is a need for an efficacious, easily administered, agent for treating acne and/or reducing sebaceous gland activity in a mammal, having little or no undesirable side effects.